1. Field of the Invention
The present invention relates to a sheet processing apparatus for ejecting sheets at such intervals that the sheets on which toner images have been formed are difficult to be adhered by the toner images and to an image forming apparatus having such a sheet processing apparatus in an apparatus main body.
2. Description of the Related Art
An image forming apparatus is an apparatus for forming an image onto a sheet. As image forming apparatuses, for example, there are a copying apparatus, a printer, a facsimile apparatus, a hybrid apparatus (multi-function apparatus) having multi-functions of those apparatuses, and the like. Among the image forming apparatuses, there is an image forming apparatus of a type in which a sheet processing apparatus for processing sheets on which images have been formed is provided in an apparatus main body or is provided as an option for the outside of the apparatus main body.
A certain type of image forming apparatus heats and fixes a toner image onto the sheet thereby forms the image on the sheet. According to such an image forming apparatus, there is a case where after the toner image was heated and fixed onto the sheet, the sheet is fed to the sheet processing apparatus before the toner image is solidified.
There is, consequently, a case where the stacked sheets are adhered by the toner images (hereinbelow, such a phenomenon is referred to as “discharge adhesion”) and when the sheets are separated, the sheet is torn or the toner image is dropped out.
As a sheet stacking apparatus which can cope with such a problem, there is an apparatus having a fan adapted to blow the air to the sheets stacked on a stacking tray in order to solidify the toner images by actively cooling the sheets (Japanese Patent Application Laid-Open No. 2007-76864).